More precision is needed when using direct injection when trying to land on a selected location.

Constructing a Minmus Rocket

*The Upper Stage (Lander)

This stage should be much lighter than the one you would use to reach The Mun. Landing on Minmus and returning to Kerbin only requires about as much fuel put together as the landing phase of a Mun visit.

*The Middle Stage (Transfer Burn)

Take advantage of the weight you have saved on your lander to pack more fuel for this one. You will need it for the trip between Kerbin and Minmus.

*The Lower Stage (Launch)

This stage should not be much different than the one you would use on a Mun attempt. If you are not feeling confident about your middle stage, it never hurts to pack a little more fuel/thrust.

Launching Into Kerbin's Orbit

Minmus Injection

While it may not be absolutely necessary, matching your orbital inclination with Minmus makes it much easier to get caught in its SOI. Set Minmus as your target and burn perpendicular to your orbital plane at one of the nodes until they read '0.0' or 'NaN'.

Similar to the Mun guide, wait until Minmus is about 4-5 degrees over the horizon (20-40 degrees in the map) to begin your burn. It will appear as a small dot above the horizon. Burn until your apoapsis intersects Minmus' orbit, and (hopefully) you will be caught.

Landing on Minmus

Your orbit, retrograde burn, and landing will all be at much lower speeds than they would be at either the Mun or Kerbin. In fact, it's unlikely that you will (or should) reach speeds above 100 m/s at any point near Minmus. Try aiming for a frozen lake if you are looking for an easier landing, close to chart datum. Minmus' large mountain ranges make for more of a challenge elsewhere on the surface. And no, it's not a big ice cream!

Returning to Kerbin

Basic method

This is a crude but effective method, using slightly more fuel than the advanced method below.
Begin a light burn until you escape Minmus' SOI, then apply retrograde thrust until your periapsis is below 65 km altitude on Kerbin. Happy Landings!

Advanced method

This method is cheaper on fuel.

Burn to raise the apoapsis to around 10,000m.

Burn prograde at apoapsis to achieve a low equatorial orbit.

When the craft is moving retrograde relative to Minmus's orbit around Kerbin, face prograde and burn again to escape velocity.

Keep burning until your periapsis around Kerbin is below 32,000m.

You will now be on a trajectory towards Kerbin. You will not need to burn again to re-enter the planet's atmosphere.